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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-10-09 17:18:14 +0000
committerStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-10-09 17:18:14 +0000
commitd6fe76c58c358498b91d21f0ca8054f6aa6e672d (patch)
tree7a351e4ddefe07831842757ddd32b46156bc69a4 /arch/ia64
parent58c8b26909f287c72a7a39d26f800ffe61e01bf3 (diff)
downloadop-kernel-dev-d6fe76c58c358498b91d21f0ca8054f6aa6e672d.zip
op-kernel-dev-d6fe76c58c358498b91d21f0ca8054f6aa6e672d.tar.gz
xen: introduce xen_alloc/free_coherent_pages
xen_swiotlb_alloc_coherent needs to allocate a coherent buffer for cpu and devices. On native x86 is sufficient to call __get_free_pages in order to get a coherent buffer, while on ARM (and potentially ARM64) we need to call the native dma_ops->alloc implementation. Introduce xen_alloc_coherent_pages to abstract the arch specific buffer allocation. Similarly introduce xen_free_coherent_pages to free a coherent buffer: on x86 is simply a call to free_pages while on ARM and ARM64 is arm_dma_ops.free. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Changes in v7: - rename __get_dma_ops to __generic_dma_ops; - call __generic_dma_ops(hwdev)->alloc/free on arm64 too. Changes in v6: - call __get_dma_ops to get the native dma_ops pointer on arm.
Diffstat (limited to 'arch/ia64')
-rw-r--r--arch/ia64/include/asm/xen/page-coherent.h24
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/ia64/include/asm/xen/page-coherent.h b/arch/ia64/include/asm/xen/page-coherent.h
new file mode 100644
index 0000000..37b929c
--- /dev/null
+++ b/arch/ia64/include/asm/xen/page-coherent.h
@@ -0,0 +1,24 @@
+#ifndef _ASM_IA64_XEN_PAGE_COHERENT_H
+#define _ASM_IA64_XEN_PAGE_COHERENT_H
+
+#include <asm/page.h>
+#include <linux/dma-attrs.h>
+#include <linux/dma-mapping.h>
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flags,
+ struct dma_attrs *attrs)
+{
+ void *vstart = (void*)__get_free_pages(flags, get_order(size));
+ *dma_handle = virt_to_phys(vstart);
+ return vstart;
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+ void *cpu_addr, dma_addr_t dma_handle,
+ struct dma_attrs *attrs)
+{
+ free_pages((unsigned long) cpu_addr, get_order(size));
+}
+
+#endif /* _ASM_IA64_XEN_PAGE_COHERENT_H */
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